def TODO
Server to MusicMan shop (sale of songs) with MySQL DB:
    1) DataBase MusicMan;
    2) Tables:
        a) users (id, name, email, is_staff);
        b) songs (id, name); 
        c) tags (id, name);
    3) Server of shop:
	a) Register and Auth;
	b) Change password;
	c) Show All songs list;
	d) Show all buying songs;
	e) Show all authors songs;
	f) Buy song;
	
    4) Client;
